CN115353116A - CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black - Google Patents

CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black Download PDF

Info

Publication number
CN115353116A
CN115353116A CN202211046139.0A CN202211046139A CN115353116A CN 115353116 A CN115353116 A CN 115353116A CN 202211046139 A CN202211046139 A CN 202211046139A CN 115353116 A CN115353116 A CN 115353116A
Authority
CN
China
Prior art keywords
sio
carbon black
white carbon
solution
gas
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
CN202211046139.0A
Other languages
Chinese (zh)
Inventor
王太进
肖明
顾黎娜
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Lvzhilan New Material Technology Co ltd
Original Assignee
Jiangsu Lvzhilan New Material Technology Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiangsu Lvzhilan New Material Technology Co ltd filed Critical Jiangsu Lvzhilan New Material Technology Co ltd
Priority to CN202211046139.0A priority Critical patent/CN115353116A/en
Publication of CN115353116A publication Critical patent/CN115353116A/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B33/00Silicon; Compounds thereof
    • C01B33/113Silicon oxides; Hydrates thereof
    • C01B33/12Silica; Hydrates thereof, e.g. lepidoic silicic acid
    • C01B33/18Preparation of finely divided silica neither in sol nor in gel form; After-treatment thereof
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/30Particle morphology extending in three dimensions
    • C01P2004/32Spheres
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/60Particles characterised by their size
    • C01P2004/61Micrometer sized, i.e. from 1-100 micrometer
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/60Optical properties, e.g. expressed in CIELAB-values

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Silicon Compounds (AREA)

Abstract

The invention relates to CO 2 And a process for preparing white carbon black by Na element self-circulation, belonging to the technical field of white carbon black preparation. The technical scheme is as follows: firstly, water glass is produced; the second step is Na 2 SiO 3 Acidifying to produce silicic acid, also known as silica gel; the third step is to adjust the pH value of the liquid, and to match with stirring and temperature control, mSiO 2 ·nH 2 The immersion time of O in the solution determines which final white carbon black product is prepared; at the same time, silica gel and silica sol can be produced. The two technical schemes are as follows: CO (carbon monoxide) 2 The process for directly preparing the white carbon black by self-circulation of Na element is called a direct method for short; CO (carbon monoxide) 2 And Na element self-circulation indirect white carbon black preparation process, which is called indirect method for short. CO in the whole process of the invention 2 Zero emission of gas; green environmental protection, low energy consumption and whole process CO 2 Zero emission of gas, raw material Na 2 CO 3 The recycling is realized, and the cost is greatly reduced.

Description

CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black
Technical Field
The invention relates to CO 2 And a process for preparing white carbon black by Na element self-circulation, belonging to the technical field of white carbon black preparation.
Background
The white carbon black is a silicon-based reinforced powder substance, is white in appearance and has porous materials, and the main component of the white carbon black is SiO 2 The internal structure and the aggregation state of the rubber additive are very similar to those of carbon black, and the rubber additive can replace the carbon black in the market of rubber additives, so the rubber additive is called white carbon black. It is an amorphous substance with a plurality of crystal water and the molecular formula is SiO 2 ·nH 2 And (O). Can be dissolved in NaOH and HF solution, and cannot be dissolved in water(H 2 O), common solvents and common acids such as H 2 SO 4 、HNO 3 、HCl、H 3 PO 4 And the like. The newly prepared product (white carbon black) has strong activity and can be combined with the moisture in the air to form fine particles.
Application of white carbon black: the white carbon black has very wide application range and very strong functions, and is highlighted in the following fields. (1) Rubber products: the white carbon black is used for replacing carbon black for reinforcement in a colored rubber product, and meets the requirements of a white or semitransparent product; the white carbon black has strong adhesive force, tear resistance, heat resistance and ageing resistance, so that the white carbon black can replace partial carbon black in black rubber products to obtain high-strength, high-heat-resistance and high-wear-resistance products, such as off-road tires, engineering tires, radial tires and the like. (2) Agricultural chemicals: in the field, such as pesticides, high-efficiency spraying fertilizers and the like, white carbon black is used as a carrier or a diluent and a disintegrating agent. (3) Daily chemical products: a transparent colour and non-transparent toothpaste using white carbon black as filler and abrasive. (4) Cementing agent: the white carbon black provides thixotropy and reinforcement for the adhesive synthesized by natural or synthetic rubber, and can improve adhesive force due to the extensibility, and has high quality and low price. (5) anti-caking agent: white carbon black can be used to enhance free-flowing properties in products such as lawn fertilizers, fungicides, grinding wheel abrasives, bleaches, phenolic injection molded urotropin, plastics of phenol and urea, in the manufacture of rubber sulfur, and in anti-caking mixtures. (6) Papermaking filling material: the white carbon black is used as the paper filler, so that the printing ink permeation resistance and the mechanical strength of the paper can be improved, the whitening effect is achieved, and the unit weight is reduced. The paper weight can be effectively reduced, the cost is reduced, and the use performance of the paper is improved. In addition, the coating can also be used in various industries such as fire-fighting agents, feeds, cosmetics, flatting agents, pigments, paints and the like. (7) The white carbon black product has structural development in the use field, the cost is greatly reduced, and the market throughput is infinite according to the physical and chemical properties of the white carbon black, such as building bricks, viscous mortar, refractory materials, road traffic and the like. With several successes toward such low ends, human reduction in greenhouse gas emissions is greatly reduced.
Silica gel, alternative name: silica gel or silicic acid gel, molecular formula: xSiO 2 ·yH 2 O, a transparent or milky granular solid with an open porous structure. An acidic liquid is added to the water glass solution and the mixture is allowed to stand to form a hydrous silicic acid gel which is solidified. Using clean water to wash out the electrolyte Na contained in the solution + And acid radical ions or ion groups, and drying to obtain the silica gel. If absorbing water, the moisture absorption can reach 40 percent, even 300 percent. The method is used for gas dehydration, liquid dehydration, chromatography, catalyst, substance surface passivation, colloid liquid preparation and the like, and can be regenerated.
Inorganic silica gel classification: with Na 2 SiO 3 As raw material, with CO 2 Inorganic silica gels produced by neutralization can be classified as: (1) fine silica gel, which is a colorless transparent or yellowish transparent glass in physical state. It is suitable for drying, moisture-proof and rust-proof. Can prevent various instruments, weapons and ammunition, electrical equipment, medicines, foods, textiles and other various packaged articles from being affected with damp, and can be used as a catalyst carrier and for dehydrating and refining organic matters. (2) The B type silica gel is milky white transparent spherical or blocky particles. The B-type colloidal pore structure is arranged between the coarse silica gel and the fine silica gel, and is used for air humidity adjustment, catalysts and carriers, pet padding and used as raw materials of fine chemical products such as chromatographic silica gel and the like. (3) The coarse-pore silica gel is a high-activity adsorption material, belongs to an amorphous substance and has a chemical molecular formula of mSiO 2 ·nH 2 And (O). Insoluble in water and any solvent, non-toxic, odorless, and non-reactive with any acid except strong alkali or F-containing acids. The appearance is white, and the paint is mainly used for gas purifiers, drying agents, acid scavengers of insulating oil and the like. In fact, only sodium silicate Na is utilized between silica gel and white carbon black 2 SiO 3 H produced after acidification 2 SiO 3 (silicic acid) is respectively obtained by treating in different ways according to requirements, and is actually mSiO 2 ·nH 2 O, that is to say, the production process of the white carbon black can also produce silica gel.
Production of white carbon black in the prior art: the production method of white carbon black mainly comprises two processes: (1) a gas phase process; (2) and (4) a precipitation method. (1) Gas phaseThe method comprises the following steps: also called pyrolysis method or dry method, the raw material is siloxane, especially hexaethyl siloxane, silicon tetrachloride and the like. In general, siCl is used 4 The gas is hydrolyzed at high temperature in a mixed gas flow of hydrogen and oxygen (air) in a combustion chamber, and the reacted gas contains SiO 2 The gas aerosol enters a condensing chamber to be retained for a period of time until flocculent SiO is formed 2 And (4) performing cyclone separation, degumming the finished product to reduce the content of HCl in the product to below the index, and finally packaging. The production of white carbon black by a gas phase method is a very expensive preparation method, and the raw material SiCl 4 The production of (a) is a complex process. The tooling matching and production of the actual production are huge, and the environmental management in the acid-related process and the post-production process is very difficult. The chemical formula is as follows:
Figure DEST_PATH_IMAGE002
the general reaction formula is as follows:
Figure DEST_PATH_IMAGE004
the white carbon black produced by the method has smooth surface, higher chemical purity and superior performance, has smaller ignition loss than that of a product produced by a precipitation method, and has the special functions of thickening and thixotropic property of liquid, preventing solid phase deposition of suspension, improving the fluidity of powder products, preventing agglomeration and disappearance and the like. (2) Preparing white carbon black by a precipitation method: the industrial water glass is the main raw material for preparing the white carbon black by a precipitation method, and only alkali metal silicate is dissolved in water and heavy metal silicate is not dissolved in water. General industrial water glass Na 2 O and SiO 2 The molar ratio of (a) to (b) is about 1. Due to H 2 SiO 3 The solubility of (silicic acid) in water is very small, about 10ppm, that is, the silicic acid is easily displaced from the silicate solution by carbonic acid, acetic acid, etc., which are weak acids, because the ionization equilibrium constant of silicic acid is very small. When bubbling CO into a relatively dilute water glass solution 2 The gas did not immediately visibly show the generation of a large amount of silicic acid precipitate because of the initialRaw silicic acid is a single molecule, which is soluble in water. Over time, unimolecular silica gels gradually polymerize into oligomeric and eventually polymeric silica gels. This phenomenon is very critical and is an important link for the variety production of silica white and silica gel by precipitation.
The method for producing white carbon black at present in China is mainly a precipitation method except a gas phase method which has huge investment and strict environmental evaluation entry system: including soda ash (Na) 2 CO 3 ) And a caustic soda process.
The soda method is Na 2 CO 3 With SiO 2 Mixing the quartz sand and the water solution according to a certain molar ratio, loading the mixture into a high-temperature furnace (a professional furnace), heating the mixture to 1260 to 1400 ℃ by using coal gas or clean coal, and adding Na 2 CO 3 With SiO 2 Reaction to form high temperature Na 2 SiO 3 The molten liquid flows out of the furnace and falls into a water pool to be cooled and crisp into granular solid powder. This solid Na 2 SiO 3 Insoluble in acid and alkali solution and water, and can be gradually dissolved by passing through a pressure kettle under the conditions of water vapor temperature not lower than 120 deg.C and pressure not lower than 0.2 MP. Liquid Na 2 SiO 3 After dilution, inorganic acids such as: h 2 SO 4 、HCl 、HNO 3 To produce the corresponding sodium salt solution (Na) 2 SO 4 、NaCl、NaNO 3 ) And polysilicic acid (mSiO) 2 ·nH 2 O), filtering to clear the electrolyte in the solution, and obtaining the rest of the solution which is the precursor (H) for producing the white carbon black 2 SiO 3 ). Adjusting the pH value of a precursor silicic acid solution, controlling the stirring speed and the liquid temperature in a mode, filtering and drying the mSiO 2 ·nH 2 And obtaining the white carbon black of the required variety by the method O.
A caustic soda method: in the first step, soluble Na is also prepared 2 SiO 3 A liquid having the formula:
Figure DEST_PATH_IMAGE006
the reaction omits two-step operation of high-temperature roasting and secondary pressure dissolution (soda process), and only needs to carry out the reaction on NaOH and SiO 2 Mixing the raw materials according to a reaction molar equivalent ratio, filling the mixture into a pressure reaction kettle filled with a proper amount of pure water, and reacting at a proper reaction temperature, time and pressure to prepare the raw material liquid water glass (Na) for producing the white carbon black 2 SiO 3 ). The method for preparing the white carbon black in the next step is the same as the subsequent process of the soda process. The cost of the soda method is lower than that of the soda method, and the technological means of the soda method is simpler than that of the soda method. In practical situations, some white carbon black manufacturers or original production licenses are produced by a soda method; perhaps water glass raw material acidification production is purchased, all the more. The analysis of the traditional process for producing the white carbon black by the soda method has the following problems: (1) CO 2 2 Discharging gas; (2) recovering the low added value of the sodium salt solution; (3) the acid-related problem is serious; (4) the overall cost of the product is extremely high; (5) the energy consumption is high in the production process, and the utilization rate of waste heat is low; (6) the downstream market for sodium salt by-products is very narrow; (7) gas pollution is difficult to control in the production process; (8) the production admission system is very strict; (9) the production of white carbon black by this method is prohibited by government or by regulation, and is not encouraged at most.
First Na 2 SiO 3 (Water glass) Process CO 2 The gas emission is large and is from chemical formula
Figure DEST_PATH_IMAGE008
It can be seen that: 1mol (mol) of Na 2 CO 3 With 1mol (mol) of SiO 2 Reacting at high temperature to generate 1mol of Na 2 SiO 3 And 1mol of CO 2 A gas. The molar mass ratio is as follows: 82, 60 → 98, from which: CO in the product 2 The gas emissions corresponded to 30.98% (theoretical) of the amount of the substances participating in the reaction or of the product. On the other hand: na (Na) 2 CO 3 With SiO 2 CO produced by combustion of fuel required for the reaction 2 Adding the two components together, if the treatment is not effective, the water glass (Na) required by white carbon black production by using said method 2 SiO 3 ) It is difficult to evaluate items by rings. Na (Na) 2 SiO 3 The solution is mixed with hydrochloric acid, nitric acid,Sulfuric acid (HCl, HNO) 3 、H 2 SO 4 ) The sodium salt solution generated by the reaction can not be discharged at will, and even if the sodium salt solution is concentrated, dried and solidified, the value is very low, and even the energy consumption cost and the cost of the process required by the concentration and drying can not be offset enough. With Na 2 SiO 3 The traditional process for preparing the white carbon black by using the water glass needs a large amount of inorganic acid, such as HCl and HNO 3 、H 2 SO 4 . Mainly because the three inorganic acids are cheap, (especially HCl and H) 2 SO 4 Is the most) and the reaction is complete and rapid. During the reaction, they react not only with Na 2 SiO 3 Reaction with Na 2 SiO 3 Other impurity elements in the solution react rapidly to ionize the solution. Thus, the white carbon black precursor H is finely filtered 2 SiO 3 When the method is used, other trace elements are removed to a great extent, and the most important is Li Qing H 2 SiO 3 Alkali metal (Na) of (1) + ) Ion thereby heating and drying H 2 SiO 3 As is well known, the white carbon black product with higher purity is very sensitive and dangerous in the acid-related industry, national control is very strict, and the application of each place has no talk, so that carbon emission and acid-related are high-voltage lines in the current and future industries and cannot be touched. As for the enterprises which still use the traditional process of soda to produce white carbon black, the enterprises have invested huge capital and the environmental protection management is continued after being upgraded and reaches the standard. The white carbon black produced by the traditional soda process has high cost, and is specifically represented in the following aspects: (1) raw material cost: a. na (Na) 2 CO 3 (soda); b. quartz sand; c. and (3) fuel. The fuel used in the past is cheap coke oven gas, low-quality oil, clean coal and the like, and only natural gas can be used at present. The soda accounts for 60% of the total raw material cost, the price of the quartz sand floats smoothly, and the cost price of the quartz sand is basically consistent when the cost price of the quartz sand is removed by manufacturers in the same industry, so that the cost price of the quartz sand can be regarded as a fixed parameter. The cost of natural gas can also be set as a fixed parameter, and other clean and cheap fuels can be sought or qualified according to actual conditions. From this it can be seen that Na 2 CO 3 Is a variable parameter (variable) which can control the cost and most directly reduce the whiteCarbon black costs. (2) A large amount of heat is released in the process of producing the water glass, and the heat energy carrier CO is 2 And a portion of the water vapor. The traditional process can only partially utilize for the second time, the utilization rate is very low, and the product cost is correspondingly higher. (3) In fact, produce Na 2 SiO 3 Then to white carbon black mSiO 2 ·nH 2 O products, relying on alkali metal sodium ions (Na +), na in the conventional art + Is used only once because it reacts with H 2 SO 4 、HCl、HNO 3 Inorganic salts are not inexpensive to regenerate after they are formed. Therefore, only Na can be continuously added in the production process 2 CO 3 The powder ensures that the cost of the white carbon black of the terminal product is high. (4) The recovery of Na salt containing inorganic acid radical ions, the neutralization of excess inorganic acid in the reaction process, the purification of water all need to invest a large amount of capital, corresponding equipment is built, the treatment cost is quite high, the return rate is almost zero, and the unit product cost is greatly increased.
Disclosure of Invention
The invention aims to provide CO 2 And the process for preparing the white carbon black by self-circulation of Na element is environment-friendly, low in energy consumption and CO in the whole process 2 Zero emission of gas, raw material Na 2 CO 3 The (soda) is recycled, the cost is greatly reduced, and the technical problems in the prior art are solved.
The technical scheme of the invention is as follows:
CO (carbon monoxide) 2 The first step of the self-circulation process for preparing white carbon black with Na element is to produce water glass (Na) 2 SiO 3 ) (ii) a The second step is Na 2 SiO 3 Acidifying to produce silicic acid, also known as silica gel; the third step is to adjust the pH value of the liquid, and to match with stirring and temperature control, mSiO 2 ·nH 2 The immersion time of O in the solution determines which final white carbon black product is prepared; at the same time, silica gel and silica sol can be produced.
Based on the above concept, the present invention has at least two technical solutions, which are the same in basic properties, of CO 2 Gas accompanied by alkali metal Na + And (3) recycling, namely: decomposition ← → synthesis is performed alternately; two techniquesThe technical scheme is as follows: 1. CO (carbon monoxide) 2 The process for directly preparing the white carbon black by self-circulation of Na element is called a direct method for short; 2. CO (carbon monoxide) 2 And Na element self-circulation indirect white carbon black preparation process, which is called indirect method for short.
CO (carbon monoxide) 2 The Na element self-circulation process for directly preparing the white carbon black has a chemical formula of
Figure DEST_PATH_IMAGE009
First step of
Figure DEST_PATH_IMAGE011
Second step of
First, na is purified in the first step 2 SiO 3 A solution; the first step is to add soda Na in the temperature range of 1260-1400 DEG C 2 CO 3 And quartz sand SiO 2 Melting in high temperature space to generate sodium silicate Na as raw material for preparing white carbon black 2 SiO 3 While releasing high-temperature gas CO 2 (ii) a This part of CO 2 CO produced by melting reaction of the two and burning of external fuel 2 (ii) a The second step is to react the CO with the same equivalent weight generated in the first step 2 As acids with water-soluble Na 2 SiO 3 By solvolytic reaction to form silicic acid H 2 SiO 3 Silicic acid is also a precursor for producing white carbon black; thus, the raw material of soda Na 2 CO 3 Carbon element in (1) as CO 2 Form (A) and Na 2 SiO 3 Reaction further produces Na 2 CO 3 (ii) a The water solubility is concentrated by a reverse osmosis membrane and the first step of high temperature CO is recycled 2 Gas waste heat and secondary supplementary heat are dried by a multi-effect evaporator to further become anhydrous powder which is used as a raw material to enter the first-step reaction; thus CO 2 Na element is circularly consumed, the molar mass of the two elements is conserved, and no CO exists in the reaction process 2 And (4) overflowing.
In the first step reaction, the fuel used for heating is methane, and CO generated by combustion 2 Gas, remaining little after using its loaded heatAmount of CO 2 The gas may be vented or temporarily stored.
The purified Na 2 SiO 3 The water for the whole process of the solution is deionized water, and Na is concentrated and dried 2 CO 3 The recovery rate of deionized water is 70%, and 30% needs process compensation.
Introducing CO 2 Post Na 2 SiO 3 Alkalinity of the solution is reduced, naFeO 2 And NaAlO 2 Begin to convert to flocculent Fe (OH) 2 And Al (OH) 3 While generating partial SiO 2 Particles and ions, with Ca 2+ 、Mn 2+ Combined into precipitates which are flocculated with Fe (OH) 2 And Al (OH) 3 Strongly adsorbing and co-precipitating, and filtering to achieve the effects of impurity removal and purification; the pH value of the solution is 11, and the process temperature is between 40 and 50 ℃; continuously introducing CO into the solution after rapid filtration 2 Gas, the reaction is completed when the pH reaches 10; the precursor H of the white carbon black produced at the moment 2 SiO 3 In CO 2 Impact stirring of the gas and formation of SiO at a temperature of 40-50 DEG C 2 Repeatedly washing the powder with deionized water to obtain almost neutral powder, washing and filtering to obtain SiO 2 And drying at 80 ℃ to obtain the spherical white carbon black with good dispersibility and uniform particle size.
Or alternatively, CO is introduced 2 Introducing Na at 40-50 deg.C by gas dispersion 2 SiO 3 In solution until silicic acid H is produced 2 SiO 3 Stirring and washing the multi-block colloid to be nearly neutral, dissolving impurity ions by using an organic acid, washing and filtering, and crushing the H blocks 2 SiO 3 Drying and crushing to obtain the final product white carbon black.
CO (carbon monoxide) 2 The process for indirectly preparing white carbon black by Na element self-circulation firstly purifies Na 2 SiO 3 Solutions from pure, high-purity limestone CaCO 3 CO produced by medium-high temperature cracking 2 Gas instead of inorganic acid and Na 2 SiO 3 Reacting to generate white carbon black precursor silicic acid H 2 SiO 3 (ii) a Washing and filtering H after the reaction 2 SiO 3 Low concentration of Na produced 2 CO 3 A solution; warp beamConcentrating to 10% Na by reverse osmosis membrane equipment 2 CO 3 Recovering the deionized water at a rate not less than 70%; 10% Na after concentration 2 CO 3 The solution is changed into liquid with the concentration of 35-50% by a high-efficiency evaporator; high-purity lime CaO generated after calcination is stirred and added into the liquid; or slowly diluting calx with hot water to obtain calx emulsion, and blending with 35-50% Na 2 CO 3 In solution;
the following reactions occur: na (Na) 2 CO 3 +Ca(OH) 2 →CaCO 3 ↓ +2NaOH; (caustic soda liquor); the reaction is exothermic, and hot water pipes can be laid around and at the bottom of the reaction tank for supplying H 2 SiO 3 With Na 2 CO 3 Heating the solution washing tank to generate NaOH and CaCO 3 The precipitated mixed solution is centrifugally dried or filter-pressed and collected to obtain high-purity CaCO 3 Drying the mixture with trace NaOH by using waste heat and then calcining the dried mixture; because the boiling point of NaOH is less than 1250 ℃, the calcining temperature is no more than 1200 ℃, naOH does not volatilize in the calcining process, and Na element is not lost in the whole process; the collected NaOH solution can be fine filtered again, after the molar concentration of NaOH in the solution is determined by using Na + detector, the superfine quartz sand is added according to the reaction molar equivalent, and the mixture is put into a pressure kettle to be heated and pressurized for reaction, the reaction temperature is not lower than 150 ℃, and Na is generated 2 SiO 3 A liquid; CO produced by repeated calcination 2 The gas, after utilizing the heat energy loaded by the gas, returns to Na 2 SiO 3 Solution reaction to produce white carbon black precursor H 2 SiO 3 And Na 2 CO 3 ; CO 2 Gas and Na element in CaCO 3 The white carbon black is produced in a circulating reciprocating and self-consuming manner under the conversion of an intermediate medium; the method realizes no carbon emission and does not participate in various inorganic acids, and the chemical formula of the indirect method is as follows:
Figure DEST_PATH_IMAGE013
the CaCO 3 Is a high-purity intermediate medium; due to the intermittency of the cyclic reaction process, CO 2 Gas is required to be provided with one after the gas is unloaded from high temperature and the heat energy is cooledThe pressure of the temporary low-pressure gas storage tank is not more than 0.1MPa.
The purified Na 2 SiO 3 The solution and the whole process water are all deionized water, and Na is concentrated and dried 2 CO 3 The recovery rate of the deionized water is 70 percent, and 30 percent of the recovery rate needs process compensation.
Introduction of CO 2 postNa 2 SiO 3 Alkalinity of the solution is reduced, naFeO 2 And NaAlO 2 Beginning to convert into flocculent Fe (OH) 2 And Al (OH) 3 While generating partial SiO 2 Particles and ions, with Ca 2+ 、Mn 2+ Combined into precipitates which are flocculated with Fe (OH) 2 And Al (OH) 3 Strongly adsorbing and co-precipitating, and filtering to achieve the effects of impurity removal and purification; the pH value of the solution is 11, and the process temperature is between 40 and 50 ℃; continuously introducing CO into the solution after the rapid filtration 2 Gas, the reaction is completed when the pH reaches 10; the white carbon black precursor H produced at the moment 2 SiO 3 In CO 2 Impact stirring of gas and formation of SiO at a temperature of 40-50 deg.C 2 Repeatedly washing the powder with deionized water to obtain almost neutral powder, washing and filtering to obtain SiO 2 And drying at 80 ℃ to obtain the spherical white carbon black with good dispersibility and uniform particle size.
Or, CO is mixed 2 Introducing Na at 40-50 deg.C for gas dispersion 2 SiO 3 In solution until silicic acid H is produced 2 SiO 3 Stirring and washing the multi-block colloid to be nearly neutral, dissolving impurity ions by using an organic acid, washing and filtering, and crushing the H blocks 2 SiO 3 Drying and crushing to obtain the final product white carbon black.
Comparison of direct and indirect methods:
1. the places where the direct method and indirect method need the same raw materials are quartz sand; the quartz sand grains required by the direct method are 70-80 meshes, are too fine and have large blowing loss in the melting process.
2. The direct method and indirect method have different processes and reaction chemical formulas for preparing the water glass.
The direct method comprises the following steps:
Figure DEST_PATH_IMAGE014
the product is high-temperature liquid Na 2 SiO 3 And the water flows into the water to be chilled into solid particles. Na is added before the raw materials enter the smelting furnace 2 CO 3 Adding the mixture and quartz sand in a molar mass ratio uniformly in batches, or adding the mixture according to Na 2 O and SiO 2 1.3 ratio calculation. Granular solid sodium silicate Na 2 SiO 3 The partial materials and deionized water are put into a pressure kettle in a proper proportion and hydrolyzed into Na under the conditions of 160-180 ℃ and not less than 0.6MPa 2 SiO 3 An aqueous solution.
The indirect method is to directly react quartz sand and NaOH (caustic soda) with appropriate amount of water in an autoclave to obtain Na, wherein the modulus of the quartz sand and the NaOH is not more than 1 2 SiO 3 An aqueous solution of the formula
Figure DEST_PATH_IMAGE016
The reaction conditions are approximately the same as those of the granular water glass dissolved in a solid state in the pressure kettle, namely the pressure is not less than 0.6MPa, and the temperature is between 160 and 170 ℃.
3. Production by indirect method through CaCO 3 Calcining and hydrolyzing.
4. Direct method for producing Na needing construction 2 CO 3 With SiO 2 (quartz sand) fused high temperature boiler; the indirect method requires the construction of a limestone pyrolysis furnace.
5. Na produced by direct process 2 CO 3 Concentrating the solution to 10% solution with reverse osmosis membrane, and evaporating with high efficiency evaporation equipment to obtain Na 2 CO 3 The powder with the water content not more than 5 percent is obtained. Then dried again to form a drying agent which is returned to the high-temperature furnace for recycling.
6. Na produced by indirect process 2 CO 3 The solution is concentrated to 10% concentration by reverse osmosis membrane, and then directly reacts with solid CaO (lime), so as to obtain NaOH solution by filtration. Since NaOH has high solubility in water, it is easy to extract by filtration.
7. The direct method has higher equipment investment than indirect method, and the main cost is 10 percent of Na 2 CO 3 On the evaporation equipment of the solution.
8. The solid water glass prepared by the direct method at high temperature needs to be dissolved into soluble liquid for the second time in a pressure kettle; the indirect method uses quartz sand and NaOH (caustic soda) to directly react in a pressure kettle to form a water glass solution.
9. The granularity of the quartz sand used in the direct method is 70-80 meshes, if the quartz sand is too fine, the quartz sand is blown to be damaged greatly in a high-temperature furnace. The finer the quartz sand used in the indirect process, the better, so that the reaction rate with NaOH in the autoclave is multiplied.
The invention uses CO 2 Introducing gas into water glass solution to produce white carbon black precursor xSiO 2 ·yH 2 O, not involving basic acids such as H 2 SO 4 、HNO 3 、HCl、H 3 PO 4 And inorganic acids that cause environmental pollution and are harmful to life.
The invention has the beneficial effects that: (1) overall process CO 2 Gas zero emission; (2) CO 2 2 With Na + Supplement each other to prepare sodium silicate Na 2 SiO 3 Required raw material Na 2 CO 3 (soda) recycle of its final product mSiO 2 ·nH 2 The cost of the O white carbon black is greatly reduced; (3) the whole process does not use inorganic acid; (4) the whole process is clean and green, and the environmental evaluation is very easy; (5) the product has high cost performance, and can be said to have the strongest competitive power in the same industry; (6) the method completely accords with the national industrial policy, plays a certain role in raising vibration regional economy, and is likely to become a new bright point of the process for producing the white carbon black by the precipitation method. In a word, the invention is established on the basis of the traditional process, and has advantages and disadvantages, clean circulation, trace amount, harmlessness and nutrient discharge. So-called "nutrient" discharge (self-defined), that is to say, the discharged trace amount of waste water in the process is not only harmless to the environment, but also beneficial, but can not be reused. Theoretically, the first step in the production of silica (precipitation) is the production of water glass (Na) 2 SiO 3 ) (ii) a The second step is Na 2 SiO 3 The acidification can also produce silicic acidCalled silica gel; and the third step is to adjust the pH value of the liquid according to market demands and to match reasonable physical processes such as stirring and temperature control. mSiO 2 ·nH 2 The immersion time of O in the solution determines which final white carbon black product is prepared. Meanwhile, silica gel and silica sol can be produced according to market requirements.
Drawings
FIG. 1 is a process flow diagram of the direct process of the present invention;
FIG. 2 is a process flow diagram of the indirect process of the present invention.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings.
The direct method comprises the following steps: has a chemical formula of
Figure DEST_PATH_IMAGE017
First step of
Figure DEST_PATH_IMAGE018
Second step of
The first step is to add soda Na in the temperature range of 1260-1400 DEG C 2 CO 3 And quartz sand SiO 2 Melting in high temperature space to generate sodium silicate Na as raw material for preparing white carbon black 2 SiO 3 While releasing high-temperature gas CO 2 (ii) a This part of CO 2 CO produced by melting reaction of the two and burning of external fuel 2 (ii) a Such as natural gas (CH) 4 ) (ii) a The second step is to react the CO with the same equivalent weight generated in the first step 2 As acids with water-soluble Na 2 SiO 3 By solvolytic reaction to form silicic acid H 2 SiO 3 The silicic acid is also a precursor for producing the white carbon black; thus, the raw material of soda Na 2 CO 3 Carbon element in (1) as CO 2 Form (b) with Na 2 SiO 3 Reaction further produces Na 2 CO 3 (ii) a The water solubility is concentrated by a reverse osmosis membrane and the first step of high temperature CO is recycled 2 The gas waste heat and secondary supplementary heat are dried by a multi-effect evaporator and further changed intoForming anhydrous powder which is used as a raw material to enter the first step reaction; thus CO 2 Na element is circularly consumed, so the production process is controllable, and no CO exists 2 Overflowing; CO produced by combustion of fuel methane 2 The gas can be discharged according to the national requirement after utilizing the heat of the load, but the CO can be discharged due to the CO 2 The gas generation amount is small, and calcium hydroxide Ca (OH) generated after the alkaline waste residue in the metallurgical industry is hydrated can be used 2 Neutralization of the emulsion to form CaCO 3 Precipitation, like this alkaline waste liquid, is everywhere visible, and the cost required is negligible.
The direct process is CO 2 And sodium element, and the carbon black produced by the direct recycling reaction method.
An indirect method: the indirect method, also called the intermediate medium method, is a pure, high-purity limestone CaCO 3 CO produced by medium-high temperature cracking 2 Gas instead of inorganic acid and Na 2 SiO 3 Reacting to generate white carbon black precursor silicic acid H 2 SiO 3 (ii) a Washing and filtering H after the reaction 2 SiO 3 Low concentration of Na produced 2 CO 3 Solution (NaHCO, which has low solubility in the washing solution as the temperature of the mixed solution in the washing vessel is not less than 50 ℃ C., near the end point of the washing process 3 Sodium bicarbonate is changed into Na with higher solubility 2 CO 3 Soda); concentrating to 10% solution by reverse osmosis membrane equipment, and recovering no less than 70% deionized water; na (Na) 2 CO 3 The dilute solution is concentrated in the same way as the direct method except that the dilute solution is concentrated and then passes through a high-efficiency evaporator Na 2 CO 3 Making into anhydrous powder, which is concentrated to 10% Na 2 CO 3 The solution is changed into liquid with the concentration of 35-50% by a high-efficiency evaporator; high-purity lime (CaO) generated after calcination is stirred and added into the liquid; or diluting calx with hot water to obtain calx emulsion, and blending with 35-50% Na 2 CO 3 The following reactions occur in solution: na (Na) 2 CO 3 +Ca(OH) 2 →CaCO 3 ↓ +2NaOH (caustic soda liquid); the reaction is exothermic, and hot water pipes (alkali-proof) can be laid at the periphery and bottom of the reaction tank for supplying H 2 SiO 3 With Na 2 CO 3 The solution washing tank is heated for use; naOH and CaCO produced 3 The precipitated mixed solution is centrifugally dried or filter-pressed and collected to obtain high-purity CaCO 3 Drying the mixture with trace NaOH by using waste heat and then calcining the dried mixture; because the boiling point of NaOH is less than 1250 ℃, the calcining temperature is not more than 1200 ℃, naOH does not volatilize in the calcining process, namely Na element is not lost in the whole process; collecting NaOH solution, optionally fine filtering with Na + After the molar concentration of NaOH in the solution is determined by a detector, adding superfine quartz sand according to the reaction molar equivalent, putting the mixture into a pressure kettle for heating and pressurizing reaction at the reaction temperature of not less than 150 ℃, and generating Na after a certain time 2 SiO 3 A liquid; CO produced by repeated calcination 2 The gas returns to Na after utilizing the heat energy loaded by the gas 2 SiO 3 Solution reaction to produce white carbon black precursor H 2 SiO 3 And Na 2 SiO 3 (ii) a Thus CO 2 Gas and Na element in CaCO 3 Circularly reciprocating and consumable production of white carbon black under the conversion of an intermediate medium; the method realizes no carbon emission and no participation of various inorganic acids, is clean and healthy, and has the chemical formula of an indirect method:
Figure DEST_PATH_IMAGE019
intermediate medium CaCO 3 The product is high purity, and can be made by oneself in one time, and food grade CaCO can be purchased in one time in the other time 3 (ii) a Homemade technology is the prior art, which is not discussed in detail herein, the loss amount in the production process is very little, and the cost increase is negligible. Due to the intermittency of the cyclic reaction process, CO 2 A temporary low-pressure gas storage tank is needed after the gas is unloaded from the high temperature and the heat energy is cooled, and the pressure of the gas storage tank is set to not more than 0.1MPa in consideration of safety factors. Calculated, the same volume of CO is obtained under the same temperature condition 2 The volume is reduced by a factor of 10 at a pressure of 0.1MPa. With such a low-pressure gas tank, the connection of the production process is controllable, and the flexibility of production is increased, above all with CO 2 The gas is not released and wasted, and the method is also in the process of producing the white carbon black by the direct methodThe essential steps of (a) and (b). No matter the white carbon black is produced by the direct method or the indirect method, na is required to be added 2 SiO 3 Solution with CO 2 Gas reaction, so if high-purity white carbon black is obtained, na is purified in the first step 2 SiO 3 A solution; the whole process of production is deionized water, which is the most basic condition; concentrating and drying Na 2 CO 3 The recovery rate of the deionized water is about 70 percent, and 30 percent of the recovery rate needs process compensation; sodium silicate solution (Na) 2 SiO 3 ) The alkalinity is very high, and the impurities of Fe and Al are mainly NaFeO 2 And NaAlO 2 The form exists; introducing CO 2 The alkalinity of the post solution is reduced and NaFeO 2 And NaAlO 2 Begin to convert to flocculent Fe (OH) 2 And Al (OH) 3 While generating partial SiO 2 Particles and ions, with Ca 2+ 、Mn 2+ Etc. are combined into precipitates which are flocculent Fe (OH) 2 And Al (OH) 3 Strongly adsorbing and coprecipitating, and filtering to remove impurities and purify, wherein the pH value of the solution is 11, and the process temperature is 40-50 ℃; the online detection by a pH value tester is sensitive and accurate. Continuously introducing CO into the solution after rapid filtration 2 Gas, the reaction is complete when the pH reaches 10. The precursor H of the white carbon black produced at the moment 2 SiO 3 In CO 2 Impact stirring of gas and formation of SiO at a temperature of 40-50 deg.C 2 Repeatedly washing the powder with deionized water to make it nearly neutral, adding small amount of non-detection organic acid such as formic acid, citric acid, or gluconic acid to control pH of the liquid to about 6.0, washing, filtering to remove residual impurity ions to the maximum extent, and filtering to obtain SiO 2 And drying at 80 ℃ to obtain the spherical white carbon black with good dispersibility and uniform particle size. CO may also be introduced 2 Introducing Na at 40-50 deg.C into gas diffusion pipe 2 SiO 3 In solution until H is produced 2 SiO 3 (silicic acid) colloidal in bulk, then washed with appropriate stirring to near neutrality, and then dissolved with the above-mentioned organic acid to remove impurity ions, such as Fe 3+ 、Al 3+ 、Mn 2+ 、Ca 2+ The plasma element is changed into soluble salt and washedFiltering, and removing H in pieces 2 SiO 3 Drying and crushing at proper temperature to obtain the final product white carbon black. Na produced in the first step by direct and indirect processes 2 SiO 3 Solutions containing particles, e.g. quartz sand, not fully reacted (direct process), caCO not fully cracked 3 (indirect method), dust particles (both direct method and indirect method). So that Na produced by the direct and indirect methods 2 SiO 3 The solution must be properly diluted and rapidly filtered to be able to react with CO 2 Gas reaction, of course CO after temperature reduction 2 The gas can be used after being washed and purified by a plurality of times of water, and the purified CO can be used 2 It is necessary to raise the temperature to the temperature required for the above reaction by using waste heat.
Comparison of direct and indirect methods:
1. the places where the direct method and indirect method need the same raw materials are quartz sand; the quartz sand grains required by the direct method are 70-80 meshes, are too fine and have large blowing loss in the melting process.
2. The direct method and indirect method have different processes and reaction chemical formulas for preparing the water glass.
The direct method comprises the following steps:
Figure 665768DEST_PATH_IMAGE017
the product is high-temperature liquid Na 2 SiO 3 And the water flows into the water to be chilled into solid particles. Na before raw materials enter a smelting furnace 2 CO 3 Adding the mixture and quartz sand in a molar mass ratio uniformly in batches, or adding the mixture according to Na 2 O and SiO 2 1.3 ratio calculation. Granular solid sodium silicate Na 2 SiO 3 The partial materials and deionized water are put into a pressure kettle in a proper proportion and hydrolyzed into Na under the conditions of 160-180 ℃ and not less than 0.6MPa 2 SiO 3 An aqueous solution.
The indirect method is characterized in that quartz sand and NaOH (caustic soda) are directly reacted with appropriate amount of water in an autoclave to obtain Na with the modulus not more than 1 2 SiO 3 An aqueous solution of the formula
Figure DEST_PATH_IMAGE020
The reaction conditions are almost the same as those of the solid granular sodium silicate dissolved in the pressure kettle, namely the pressure is not less than 0.6MPa, and the temperature is between 160 and 170 ℃.
3. Production by indirect method through CaCO 3 Calcining and hydrolyzing.
4. Direct method for producing Na needing construction 2 CO 3 With SiO 2 (quartz sand) fused high temperature boiler; the indirect method requires the construction of a limestone pyrolysis furnace.
5. Na produced by direct process 2 CO 3 Concentrating the solution to 10% solution with reverse osmosis membrane, and evaporating with high efficiency evaporation equipment to obtain Na 2 CO 3 The powder with the water content not more than 5 percent is obtained. Then dried again to form the dry agent which returns to the high temperature furnace for recycling.
6. Na produced by an indirect process 2 CO 3 The solution is concentrated to 10% concentration by reverse osmosis membrane, and then directly reacts with solid CaO (lime), so as to obtain NaOH solution by filtration. Since NaOH has high solubility in water, it is easy to leach.
7. The direct method has higher equipment investment than indirect method, and the main cost is 10 percent of Na 2 CO 3 On the evaporation equipment of the solution.
8. The solid water glass prepared by the direct method at high temperature needs to be dissolved into soluble liquid for the second time in a pressure kettle; the indirect method uses quartz sand and NaOH (caustic soda) to directly react in a pressure kettle to form a water glass solution.
9. The quartz sand used in the direct method has the granularity of 70-80 meshes, if the quartz sand is too fine, the blowing loss is larger in a high-temperature furnace. The indirect method uses finer quartz sand, the better, so that the reaction speed with NaOH in the autoclave is multiplied.
The process for preparing white carbon black by a direct method comprises the following specific processes:
1. according to the molar equivalent ratio of the reaction, 70-80 meshes of quartz sand and soda (Na) are mixed 2 CO 3 ) Mixing uniformly, and feeding into a high temperature furnace (at 1260-1400 deg.C) in batches, wherein several furnaces are arranged in the furnaceSupplying air to the burner, burning and heating; the gas is burnt into clean energy natural gas;
2. na melted in high temperature furnace 2 SiO 3 The (water glass) liquid flows out and enters a water tank outside the furnace to be cooled and embrittled into solid particles (Na) 2 SiO 3 );
3. The granular solid water glass is crushed and refined so as to be changed into water-soluble liquid in the next step and accelerate the hydrolysis speed;
4. putting powdery water glass into a pressure kettle, injecting deionized water to reach a certain solid-liquid ratio, and then heating for hydrolysis;
5. hydrolyzed Na 2 SiO 3 The solution temperature is higher, the pressure kettle is switched to water cooling by heating a cavity pipeline, and after decompression, normal temperature deionized water is injected into the kettle to dilute Na 2 SiO 3 A solution;
6. rapidly filtering the diluted Na 2 SiO 3 Filtering the solution to obtain solid residue, transferring the filtrate to a carbonization reaction tank A (hereinafter referred to as CA), returning to a high temperature furnace (mainly quartz sand), introducing CO 2 Gas, make Na in the reaction tank 2 SiO 3 Liquid with CO 2 Gas reaction, i.e.
Figure DEST_PATH_IMAGE021
The air supply system is adjustable, the solution temperature is controlled at 40-50 ℃, the trace residue is accumulated and dried, and a proper amount of Na is added 2 CO 3 Returning to the high-temperature furnace for reaction again;
heating the solution in CA by using high-temperature melting reaction CO 2 Pure air is heated by the waste heat of the gas through a heat exchanger, and the hot air is blown into the CA to heat the CA;
controlling the temperature of liquid in CA to be 40-50 ℃, and accelerating the reaction speed; secondly, to eliminate NaHCO with low solubility in the solution 3 (baking soda) in a form so as to be quick to wash. Thirdly, the white carbon black precursor is generated to be flocculent H 2 SiO 3 Hardening, granulating and dispersing;
9. on the CA is provided withThe pH value detector displays the pH value on line at any time; CO at a pH of approximately 10, preferably 9.8 2 Stopping supplying air, rapidly filtering to remove flocculent Fe (OH) 2 、Al (OH) 3 And Ca adsorbed thereto 2+ 、Mg 2+ And the like; transferring the filtrate to the next reaction tank, hereinafter referred to as CB, soaking pure hot air in liquid, stirring, supplying heat, heating, and adding CO 2 The gas is continuously supplied for reaction until the pH value is close to 11, preferably 10.8, and the reaction is completely finished; hydrated SiO in CB 2 Repeatedly washing to neutral, press-filtering or spin-drying, pulverizing in intermittent vacuum dryer, collecting, and packaging; the drying temperature reaches the product requirement at 80 ℃ because of a vacuum device; reacting in CA to pH 11, washing to neutral, adding organic acid (formic acid, citric acid, and gluconic acid) to pH 6, reacting impurities to obtain soluble salt, filtering to neutral, press-filtering or spin-drying, oven-drying at 80 deg.C, pulverizing, and packaging; the pH value of the process is close to neutral, impurity elements are non-toxic and harmless, the filtrate is environment-friendly and free of inspection, the filtrate amount is not large, the filtrate completely reaches the standard, and the filtrate can be discharged randomly; the finished product has poor dispersibility, is a non-spherical body, has small specific surface area and low price;
10. all filtrates need to be cooled in a water tower to a temperature not higher than 40 deg.C, and the filtrate only contains Na 2 CO 3 The dilute solution of (A) is concentrated by a reverse osmosis membrane with the temperature not higher than 40 DEG C 2 CO 3 The solution to a concentration of 10%;
11.10% of Na 2 CO 3 Evaporating the solution to Na by a high-efficiency evaporator 2 CO 3 Semi-wet with little moisture;
12. drying semi-wet Na by vacuum method 2 CO 3 Collecting the raw materials for recycling; the evaporation energy is waste heat or waste heat is matched with a small amount of electric energy;
13. CO produced by combustion of natural gas 2 After the gas is cooled, the gas can react with NaOH solution to form high-concentration Na 2 CO 3 Solution with 10% Na 2 CO 3 The solution enters a high-efficiency evaporator, and then is crystallized and dried to be used as compensation of raw material loss;
14. preparation of Na 2 SiO 3 The steam boiler is arranged at the high-temperature furnace (water glass) and utilizes high-temperature CO 2 Preparation of high-pressure steam from gas for crystallization of Na by high-efficiency evaporator 2 CO 3 The primary heat source of (2); intermediate temperature CO of the overflow 2 The gas transfers heat to the purified air through a heat exchanger, and the middle-temperature air is used for Na 2 SiO 3 Solution with CO 2 Stirring and heating the liquid (optionally open and close). Residual high heat CO 2 Transferring heat to the deionized water (the deionized water is reserved for repeatedly washing the materials) through a heat exchanger;
15. due to CO 2 The whole gas process is a closed cycle, and CO is required to be arranged for starting production and solving the problem of connection of each process link in the production process 2 The pressure of the gas low-pressure gas storage tank is not more than 0.1MPa, thus CO 2 The gas is flexibly used, and 100% of the gas is not discharged outside;
16. in view of the process of leading and lagging, a regenerator is also needed, which is similar to a hot blast stove in the metallurgical industry, and high-temperature CO which is not used temporarily 2 The heat of the gas is unloaded therein for subsequent flexible use; direct method for producing white carbon black and CO 2 Na element is self-consumed in a closed cycle, and the method is clean and environment-friendly, and greatly reduces the cost;
17. regenerator and steam boiler high temperature CO 2 Gas can be switched between the two (high temperature ceramic valve);
18. the hot air heats the liquid in the reaction tank to be mixed with CO 2 Isolating, heating and introducing CO 2 Reacting;
the CA (direct method carbonization reaction tanks) can be connected in parallel or used independently, and excess CO is reacted by CA 2 Gas is sent into the main pipeline by the compressor;
20. medium temperature CO overflowed from pressure boiler at high temperature furnace 2 The gas is provided with two heat exchangers, one is a purified air heat exchanger, and the heated purified air is heated by the liquid of the carbon separation tank; the other is in heat exchange with the standby deionized water for repeatedly washing the materials.
The process for preparing the white carbon black by the indirect method comprises the following specific flow:
1. adding refined quartz sand and NaOH with the same molar equivalent into a pressure kettle, and preparing Na in advance 2 SiO 3 The modulus of the solution is not more than 2.8;
2. limestone (CaCO) 3 ) The calcining furnace is adopted, the limestone needs to have a smooth surface and has an effective calcium oxide content which is not less than 52 percent. The fuel can be natural gas, and limestone can be repeatedly used;
Figure DEST_PATH_IMAGE023
CO produced 2 With the last step Na 2 SiO 3 Solution reaction (namely a two-step carbonization method and a one-step carbonization method);
Figure DEST_PATH_IMAGE025
na produced 2 CO 3 The diluted solution was concentrated to a 10% strength solution by reverse osmosis. The cooling of the batch in this solution occurs with lime (CaO):
Figure DEST_PATH_IMAGE027
CaCO remaining after filtration 3 Sand material, high-temperature CO discharged from limestone calcining furnace 2 The drying and preheating of the gas and the high-temperature CaO are put into the limestone calcining furnace again for recycling, that is, CO 2 Recycling gas and Na elements;
3. the calcination and the preheating drying of the limestone powder can be performed in a one-time mode in consideration of the thermal efficiency and dust control factors. Namely: calcination of CaO lime from lump limestone, lime with 10% Na 2 CO 3 After the solution reaction, the residual CaCO is filter-pressed 3 Washing the powder with natural water, neutralizing with a small amount of cheap organic acid, and drying the high-purity lime powder for sale by using waste heat. The weight of the high-purity stone powder is almost equal to that of the raw material limestone, but the price of the high-purity stone powder is not less than 5 times of that of the limestone. High-purity stoneThe powder can be used for making products which are not seen everywhere in our life, such as plastics, calcium tablets, cosmetics, clothes, toothpaste, etc. The stone powder is high in purity and ultrafine, the ash powder is widely used in the industries of rubber, ceramics, cement, glass, refractory materials, process construction, papermaking and the like, and the cost of the process raw materials is slightly reduced after the process raw materials are sold;
4. indirect processes do not require the concentration of Na as in the direct processes 2 CO 3 And the water is evaporated and dehydrated again by a high-efficiency evaporator, so that certain capital investment is reduced, and the production rhythm is accelerated. Such as 10% Na 2 CO 3 The concentration of NaOH solution which is obtained by the reaction and press filtration of the solution and CaO (lime) is low, a group of small efficient evaporators can be additionally arranged, and the concentration of 10 percent Na is improved 2 CO 3 The concentration of the solution is obtained; but at the same time, a pressure boiler is also additionally arranged to completely utilize waste heat for evaporation; caO and Na may also be added 2 CO 3 Appropriate amount of supplementary powder Na in reaction tank 2 CO 3 (much cheaper than NaOH);
5. indirect processes, e.g. using limestone unidirectional processes as described above, i.e. CaCO 3 Can not be recycled and used for preparing Na 2 SiO 3 The subsequent technological process for producing white carbon black is the same as that of the direct method, and equipment tools are basically the same except for indirect method stone powder recovery tools, and are only divided by the size of the tools.
Direct and indirect trial production examples:
1. direct method, because of trial production and limitation of conditions, na is not contained 2 CO 3 The high-temperature furnace for preparing the water glass with the quartz sand can only be purchased from the market, and the water-soluble Na produced by a soda process 2 SiO 3
a. Using a 50L transparent plastic container, 2kg of water-soluble Na was added 2 SiO 3 Pouring into a container, and adding deionized water to prepare a 30% solution.
b. CO 2 The gas steel cylinder is in soft connection with a porous spray head, an upright tube strip which is fixed on the support and can rotate left and right is arranged between the spray head and the soft connection, the spray head extends into the bottom of the container and manually rotates left and right, and an online pH value detector is arranged at the edge of the container. The slow CO supply was started 2 The gas is used for generating a gas, and the gas is used for generating a gas,about 10 minutes, the liquid gradually turns into very thin white, observed with a magnifying glass, and jumps before the pH value shows a number of 9.7 and 9.8, and the CO is immediately turned off 2 And the gas valve stops supplying gas. The batch filtration with large pieces of filter paper is painful, and after the batch filtration, the filter paper has few impurities. The filtrate was then returned to the reaction vessel and CO was continuously fed 2 The gas flow is kept constant, the stirring speed is doubled, and after about 6 minutes, the liquid is quickly whitened and the CO is reduced 2 And (3) gradually increasing the air flow and the liquid, wherein the air bubbles are blown out from the upper part of the liquid level and gradually enlarged after 3 minutes until the air bubbles are unchanged, and at the moment, closing the air supply valve.
The liquid has no floccule, is uniformly dispersed and is thick white, and the particles are difficult to see by a magnifier. Washing with deionized water at 50 deg.C for 3 times, and filtering to neutrality to obtain white soft extract. Spreading the material on filter paper, and dehydrating in microwave oven at moderate temperature. After the dehydration is finished, the materials are put into a plastic sample bag and repeatedly kneaded to be subjected to particle size detection, and the particle size is detected according to the D10 standard: 2-3 microns in size of 3.2%; 5.6% of 4-5 microns; 8-10 microns accounting for 32.7%;12-15 microns account for 18.9 percent, and the whiteness is 97.8. The white carbon black morphology image shows that about 55% is regular sphericization, about 30% of more spherical shape, and the others are non-sphericization. This is the qualitative result of the white carbon black prepared by the two-step carbonization method. Because of the condition restrictions, quantitative tests cannot be performed. The sample is analyzed by a detection organization certified by the national ISO and comprises the following components:
Figure DEST_PATH_IMAGE029
2. direct method, one-step carbon is trial-produced by adding organic acid; the equipment tooling is the same as the two-step carbonization method of the direct method. Using CO only once 2 Gas will Na 2 SiO 3 The solution reacts to form flocculent H 2 SiO 3 Washing and filtering silicic acid to be neutral, wherein the solid-to-liquid ratio is about 3, adding 60% citric acid, heating the liquid to 80 ℃ when the pH value is 6, stirring and reacting for about 10 minutes, washing and filtering again to be neutral, putting the filtered dry material into a microwave oven, drying at medium temperature, and filling white carbon black into the microwave ovenAnd (5) repeatedly rubbing the sample bag for detection.
D10 standard results of 10-15vm account for 72.2%,20-30vm account for 21.9%.
The form is as follows: no sphericizing body and whiteness of 98.2%
The assay components were as follows:
Figure DEST_PATH_IMAGE031
3. trial production of white carbon black by an indirect method:
a. preparing one 500ml small autoclave;
b. the highest temperature is 500 ℃ of the drying box;
c. the autoclave was mounted in a box and rotated instead of stirring;
d. roasting high-calcium stone by using a muffle furnace to prepare CaO;
e. mixing 50% of Na 2 CO 3 Pouring the solution into a beaker, weighing white lime (the effective CaO content is 95%) with equivalent molar weight of effective CaO, slowly pouring into the beaker, and stirring to make Na 2 CO 3 And Ca (OH) 2 And (2) fully reacting, filtering out a NaOH solution by using filter paper, adding the NaOH solution into an autoclave, adding equivalent 200-mesh 99% (SiO 2 content) quartz sand, adding deionized water until the liquid-solid ratio is 3 2 SiO 3 And (3) solution. Filtered off Na 2 SiO 3 The solution was poured into a 1000ml beaker and the stirrer was automatically stirred and heated. The white carbon black is prepared by a two-step carbonization method, and the result is as follows:
granularity: d10:2-3vm accounts for 27.6%
4-5vm accounts for 51.8%
8-10vm accounts for 16.3 percent
12-15vm accounts for 3.9%
Whiteness degree: 98
The form is as follows: the spherical shape accounts for about 60.2%
The more spherical shape accounts for about 33.6 percent
Others being non-spherical
The invention requires that:
1.CO 2 na element is not discharged in self circulation;
2. only the impurity ions can be dissolved by organic acid, and the environment is not polluted;
3. mainly the self-heat-production energy.

Claims (10)

1. CO (carbon monoxide) 2 The process for directly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: has a chemical formula of
Figure 850789DEST_PATH_IMAGE001
First step of
Figure 511578DEST_PATH_IMAGE002
Second step of
First, na is purified 2 SiO 3 A solution; the first step is to add soda Na in the temperature range of 1260-1400 DEG C 2 CO 3 And quartz sand SiO 2 Raw material sodium silicate Na for preparing white carbon black by melting in high-temperature space 2 SiO 3 While releasing high-temperature gas CO 2 (ii) a This part of CO 2 CO produced by melting reaction of the two and burning of external fuel 2 (ii) a The second step is to react the CO with the same equivalent weight generated in the first step 2 As acids with water-soluble Na 2 SiO 3 By solvolytic reaction to form silicic acid H 2 SiO 3 The silicic acid is also a precursor for producing the white carbon black; thus, the raw material of soda Na 2 CO 3 Carbon in the form of CO 2 Form (b) with Na 2 SiO 3 Reaction further produces Na 2 CO 3 (ii) a The water solubility of the product is concentrated by a reverse osmosis membrane and then the first step of high temperature CO is recycled 2 The gas waste heat and the secondary supplementary heat are dried by a multi-effect evaporator to further become anhydrous powder which is also used as a raw material to enter a first-step reaction; thus CO 2 Na element is circularly consumed, the molar mass of the two elements is conserved, and no CO exists in the reaction process 2 And (4) overflowing.
2. CO according to claim 1 2 And preparing white pigment directly by self-circulation of Na elementThe carbon black process is characterized by comprising the following steps: in the first step reaction, the fuel used for heating is methane, and CO generated by combustion 2 Gas, a small amount of CO remaining after using its loaded heat 2 The gas may be vented or temporarily stored.
3. A CO according to claim 1 or 2 2 The process for directly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: the purified Na 2 SiO 3 The water for the whole process of the solution is deionized water, and Na is concentrated and dried 2 CO 3 The recovery rate of deionized water is 70%, and 30% needs process compensation.
4. A CO according to claim 1 or 2 2 The process for directly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: introducing CO 2 Post Na 2 SiO 3 Alkalinity of the solution is reduced, naFeO 2 And NaAlO 2 Begin to convert to flocculent Fe (OH) 2 And Al (OH) 3 While generating partial SiO 2 Particles and ions, with Ca 2+ 、Mn 2+ Combined into precipitates which are flocculated with Fe (OH) 2 And Al (OH) 3 Strongly adsorbing and co-precipitating, and filtering to achieve the effects of removing impurities and purifying; the pH value of the solution is 11, and the process temperature is between 40 and 50 ℃; continuously introducing CO into the solution after rapid filtration 2 Gas, the reaction having finished when the pH reached 10; the white carbon black precursor H produced at the moment 2 SiO 3 In CO 2 Impact stirring of gas and formation of SiO at a temperature of 40-50 deg.C 2 Repeatedly washing the powder with deionized water to obtain almost neutral powder, washing and filtering to obtain SiO 2 And drying at 80 ℃ to obtain the spherical white carbon black with good dispersity and uniform particle size.
5. A CO according to claim 1 or 2 2 The process for directly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: CO is introduced into 2 Introducing Na at 40-50 deg.C by gas dispersion 2 SiO 3 In solution until silicic acid H is produced 2 SiO 3 Stirring and washing the multi-block colloid to be nearly neutral, dissolving impurity ions by using an organic acid, washing and filtering, and crushing the H blocks 2 SiO 3 Drying and crushing to obtain the final product white carbon black.
6. CO (carbon monoxide) 2 The process for indirectly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: first, na is purified 2 SiO 3 Solutions from pure, high-purity limestone CaCO 3 CO produced by medium-high temperature cracking 2 Gas instead of inorganic acid and Na 2 SiO 3 Reacting to generate white carbon black precursor silicic acid H 2 SiO 3 (ii) a Washing and filtering H after the reaction 2 SiO 3 Low concentration of Na produced 2 CO 3 A solution; concentrating to 10% Na by reverse osmosis membrane equipment 2 CO 3 Recovering the deionized water not less than 70%; 10% Na after concentration 2 CO 3 The solution is changed into liquid with the concentration of 35-50% by a high-efficiency evaporator; high-purity lime CaO generated after calcination is stirred and added into the liquid; or slowly diluting calx with hot water to obtain calx emulsion, and blending with 35-50% Na 2 CO 3 In solution;
the following reactions occur: na (Na) 2 CO 3 +Ca(OH) 2 →CaCO 3 ↓ +2NaOH; the reaction is exothermic, and hot water pipes can be laid around and at the bottom of the reaction tank for supplying H 2 SiO 3 With Na 2 CO 3 Heating the solution washing tank to generate NaOH and CaCO 3 The precipitate mixed liquor is centrifugally dried or filter-pressed and collected to obtain high-purity CaCO 3 Drying the mixture with trace NaOH by using waste heat and then calcining the dried mixture; because the boiling point of NaOH is less than 1250 ℃, the calcining temperature is no more than 1200 ℃, naOH does not volatilize in the calcining process, and Na element is not lost in the whole process; the collected NaOH solution can be fine filtered again, after the molar concentration of NaOH in the solution is determined by using Na + detector, the superfine quartz sand is added according to the reaction molar equivalent, and the mixture is put into a pressure kettle to be heated and pressurized for reaction, the reaction temperature is not lower than 150 ℃, and Na is generated 2 SiO 3 A liquid; CO produced by repeated calcination 2 Gas in the process of utilizing itThe loaded heat energy is then returned to Na 2 SiO 3 Solution reaction to produce white carbon black precursor H 2 SiO 3 And Na 2 CO 3 ; CO 2 Gas and Na element in CaCO 3 The white carbon black is produced in a circulating reciprocating and self-consuming manner under the conversion of an intermediate medium; the method realizes no carbon emission and does not participate in various inorganic acids, and the chemical formula of the indirect method is as follows:
Figure 548454DEST_PATH_IMAGE003
7. CO according to claim 6 2 The process for indirectly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: the CaCO 3 Is a high-purity intermediate medium; due to the intermittency of the cyclic reaction process, CO 2 After the gas is unloaded from the high temperature and the heat energy is cooled, a temporary low-pressure gas storage tank is needed, and the pressure of the gas storage tank is set to not more than 0.1MPa.
8. A CO according to claim 6 or 7 2 The process for indirectly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: the purified Na 2 SiO 3 The solution and the whole process water are all deionized water, and Na is concentrated and dried 2 CO 3 The recovery rate of deionized water is 70%, and 30% needs process compensation.
9. A CO according to claim 6 or 7 2 The process for indirectly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: introducing CO 2 Post Na 2 SiO 3 Alkalinity of the solution is reduced, naFeO 2 And NaAlO 2 Beginning to convert into flocculent Fe (OH) 2 And Al (OH) 3 While generating partial SiO 2 Particles and ions, with Ca 2+ 、Mn 2+ Combined into precipitates which are flocculated with Fe (OH) 2 And Al (OH) 3 Strongly adsorbing and co-precipitating, and filtering to achieve the effects of removing impurities and purifying; the pH value of the solution is 11 and the process temperature is 40-50 DEG CSpacing; continuously introducing CO into the solution after rapid filtration 2 Gas, the reaction is completed when the pH reaches 10; the precursor H of the white carbon black produced at the moment 2 SiO 3 In CO 2 Impact stirring of the gas and formation of SiO at a temperature of 40-50 DEG C 2 Repeatedly washing the powder with deionized water to obtain almost neutral powder, washing and filtering to obtain SiO 2 And drying at 80 ℃ to obtain the spherical white carbon black with good dispersibility and uniform particle size.
10. A CO according to claim 6 or 7 2 The process for indirectly preparing the white carbon black by Na element self-circulation is characterized by comprising the following steps: introducing CO 2 Introducing Na at 40-50 deg.C for gas dispersion 2 SiO 3 In solution until silicic acid H is produced 2 SiO 3 Stirring and washing the multi-block colloid to be nearly neutral, dissolving impurity ions by using an organic acid, washing and filtering, and crushing the H blocks 2 SiO 3 Drying and crushing to obtain the final product white carbon black.
CN202211046139.0A 2022-08-30 2022-08-30 CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black Withdrawn CN115353116A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211046139.0A CN115353116A (en) 2022-08-30 2022-08-30 CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211046139.0A CN115353116A (en) 2022-08-30 2022-08-30 CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black

Publications (1)

Publication Number Publication Date
CN115353116A true CN115353116A (en) 2022-11-18

Family

ID=84005499

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211046139.0A Withdrawn CN115353116A (en) 2022-08-30 2022-08-30 CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black

Country Status (1)

Country Link
CN (1) CN115353116A (en)

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101704525A (en) * 2009-11-23 2010-05-12 中煤平朔煤业有限责任公司 Preparation method of high-quality white carbon black for rubber
CN101898776A (en) * 2009-05-27 2010-12-01 北京紫光英力化工技术有限公司 New process for co-producing ultra-fine white carbon black and calcium carbonate
CN102424392A (en) * 2011-09-11 2012-04-25 中国科学院过程工程研究所 Method for preparing white carbon black cogeneration nanometer calcium carbonate by integrally utilizing micro silicon powder
CN106276935A (en) * 2016-07-26 2017-01-04 岳阳明科催化技术有限公司 Waterglass co-producing white carbon black cleanly production technique
CN109485053A (en) * 2018-12-24 2019-03-19 江西双龙硅材料科技有限公司 A method of white carbon black co-product soda ash and sodium metasilicate are prepared using carbon dioxide gas
CN112707428A (en) * 2021-01-27 2021-04-27 北京化工大学 Combined preparation method of nano calcium carbonate and pseudo-boehmite or white carbon black
CN113603100A (en) * 2021-08-31 2021-11-05 江苏绿之蓝新材料科技有限公司 Method for controlling carbon emission in metallurgical industry

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101898776A (en) * 2009-05-27 2010-12-01 北京紫光英力化工技术有限公司 New process for co-producing ultra-fine white carbon black and calcium carbonate
CN101704525A (en) * 2009-11-23 2010-05-12 中煤平朔煤业有限责任公司 Preparation method of high-quality white carbon black for rubber
CN102424392A (en) * 2011-09-11 2012-04-25 中国科学院过程工程研究所 Method for preparing white carbon black cogeneration nanometer calcium carbonate by integrally utilizing micro silicon powder
CN106276935A (en) * 2016-07-26 2017-01-04 岳阳明科催化技术有限公司 Waterglass co-producing white carbon black cleanly production technique
CN109485053A (en) * 2018-12-24 2019-03-19 江西双龙硅材料科技有限公司 A method of white carbon black co-product soda ash and sodium metasilicate are prepared using carbon dioxide gas
CN112707428A (en) * 2021-01-27 2021-04-27 北京化工大学 Combined preparation method of nano calcium carbonate and pseudo-boehmite or white carbon black
CN113603100A (en) * 2021-08-31 2021-11-05 江苏绿之蓝新材料科技有限公司 Method for controlling carbon emission in metallurgical industry

Similar Documents

Publication Publication Date Title
CN101979443B (en) Method for producing modified white carbon black
JP4537379B2 (en) Process and apparatus for producing precipitated silica from rice husk ash
CN102424392A (en) Method for preparing white carbon black cogeneration nanometer calcium carbonate by integrally utilizing micro silicon powder
CN102320615B (en) A kind of take SILICA FUME as the method that precipitated silica is prepared in raw material carbonization
CN101077777B (en) Method for preparing white carbon black from secondary carbon component
CN105197968A (en) Method and device for producing high-purity magnesium oxide and co-producing industrial concentrated hydrochloric acid through partially hydrated magnesium chloride fluidization pyrolysis
JP2016504251A (en) Aluminum ion purification method
CN102910665B (en) Method for producing industrial grade calcium chloride by taking calcium carbide slurry as raw material
CN101774591B (en) Production technology of white microsphere high-strength white carbon black
CN102190309A (en) Method for lowering pH value of active calcium silicate
CN102531001A (en) Comprehensive soda ash producing process and product application thereof
CN106276935B (en) Waterglass co-producing white carbon black cleanly production technique
CN101445254A (en) Method for producing 4A molecular sieve
JP7100093B2 (en) Calcium magnesium carbonate production system with calcium magnesium ion solution based on carbon dioxide leaching
CN103466637A (en) Method for producing precipitate silicon dioxide by using sodium bicarbonate to control supersaturation degree
CN101704526B (en) Method for producing white carbon black and active carbon by using residual rice hull ash after gasification
CN1101782C (en) Technological process for producing aluminium salt and silicate by using coal gangue
CN1699163A (en) Process for producing white carbon black and sodium sulphite by sodium sulfate method
CN112110465A (en) Preparation method of polyaluminium chloride for polyaluminium chloride flocculating agent
CN103466635B (en) Preparation method for silicon dioxide
CN112441621A (en) Comprehensive utilization method of manganese-rich slag
CN105692668A (en) Method for preparing high-molecule-ratio cryolite from coal gangue and fly ash
CN109354072B (en) Process for harmlessly producing iron oxide red pigment by alkali circulation method
CN102249247A (en) Circulatory production process for superfine silicon dioxide
CN115353116A (en) CO (carbon monoxide) 2 Na element self-circulation preparation process of white carbon black

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WW01 Invention patent application withdrawn after publication
WW01 Invention patent application withdrawn after publication

Application publication date: 20221118